Multirotor

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A DJI phantom 1, a quadcopter DJI Phantom 1 1530564a.jpg
A DJI phantom 1, a quadcopter

A multirotor [1] or multicopter is a rotorcraft with more than two lift-generating rotors. An advantage of multirotor aircraft is the simpler rotor mechanics required for flight control. Unlike single- and double-rotor helicopters which use complex variable pitch rotors whose pitch varies as the blade rotates for flight stability and control, multirotors often use fixed-pitch blades; control of vehicle motion is achieved by varying the relative speed of each rotor to change the thrust and torque produced by each.

Contents

Due to their ease of both construction and control, multirotor aircraft are frequently used in radio control aircraft and unmanned aerial vehicle (UAV) (drone) projects [2] [3] [4] [5] [6] [7] in which the names tricopter, quadcopter , hexacopter and octocopter are frequently used to refer to 3-, 4-, 6- and 8-rotor rotorcraft, respectively. [8] There is also the X8 (also called octo-quad) configuration that is similar to the quadracopter design, except that it has eight rotors; the lower of which have a reversed rotation direction. [9]

Hexacopter. The Hexacopter.jpg
Hexacopter.

In order to allow more power and stability at reduced weight, coaxial rotors can be employed, in which each arm has two motors, running in opposite directions which cancels out rotational torque (one facing up and one facing down). [11]

Also possible is the addition of horizontal propellers [12] [13] [14] These types of rotorcraft (which have just 4 vertical propellers) are called quadplanes. [15]

Rotor Configurations

Examples

OnyxStar XENA-8F coax foldable drone from AltiGator OnyxStar XENA-8F coax foldable and pliable drone.jpg
OnyxStar XENA-8F coax foldable drone from AltiGator

Related Research Articles

<span class="mw-page-title-main">Tiltrotor</span> Aircraft type

A tiltrotor is an aircraft that generates lift and propulsion by way of one or more powered rotors mounted on rotating shafts or nacelles usually at the ends of a fixed wing. Almost all tiltrotors use a transverse rotor design, with a few exceptions that use other multirotor layouts.

<span class="mw-page-title-main">Vortex ring state</span> Aerodynamic condition related to helicopter flight

The vortex ring state (VRS) is a dangerous aerodynamic condition that may arise in helicopter flight, when a vortex ring system engulfs the rotor, causing severe loss of lift. Often the term settling with power is used as a synonym, e.g., in Australia, the UK, and the USA, but not in Canada, which uses the latter term for a different phenomenon.

<span class="mw-page-title-main">Radio-controlled helicopter</span>

A radio-controlled helicopter is model aircraft which is distinct from a RC airplane because of the differences in construction, aerodynamics, and flight training. Several basic designs of RC helicopters exist, of which some are more maneuverable than others. The more maneuverable designs are often harder to fly, but benefit from greater aerobatic capabilities.

<span class="mw-page-title-main">Helicopter flight controls</span> Instruments used in helicopter flight

Helicopter flight controls are used to achieve and maintain controlled aerodynamic helicopter flight. Changes to the aircraft flight control system transmit mechanically to the rotor, producing aerodynamic effects on the rotor blades that make the helicopter move in a desired way. To tilt forward and back (pitch) or sideways (roll) requires that the controls alter the angle of attack of the main rotor blades cyclically during rotation, creating differing amounts of lift at different points in the cycle. To increase or decrease overall lift requires that the controls alter the angle of attack for all blades collectively by equal amounts at the same time, resulting in ascent, descent, acceleration and deceleration.

<span class="mw-page-title-main">Tail rotor</span>

The tail rotor is a smaller rotor mounted vertically or near-vertically at the tail of a traditional single-rotor helicopter, where it rotates to generate a propeller-like horizontal thrust in the same direction as the main rotor's rotation. The tail rotor's position and distance from the helicopter's center of mass allow it to develop enough thrust leverage to counter the reactional torque exerted on the fuselage by the spinning of the main rotor. Without the tail rotor or other anti-torque mechanisms, the helicopter would be constantly spinning in the opposite direction of the main rotor when flying.

<span class="mw-page-title-main">Coaxial-rotor aircraft</span> Helicopter with two sets of rotor blades placed on top of each other

A coaxial-rotor aircraft is an aircraft whose rotors are mounted one above the other on concentric shafts, with the same axis of rotation, but turning in opposite directions (contra-rotating).

<span class="mw-page-title-main">Helicopter rotor</span> Aircraft component

On a helicopter, the main rotor or rotor system is the combination of several rotary wings with a control system, that generates the aerodynamic lift force that supports the weight of the helicopter, and the thrust that counteracts aerodynamic drag in forward flight. Each main rotor is mounted on a vertical mast over the top of the helicopter, as opposed to a helicopter tail rotor, which connects through a combination of drive shaft(s) and gearboxes along the tail boom. The blade pitch is typically controlled by the pilot using the helicopter flight controls. Helicopters are one example of rotary-wing aircraft (rotorcraft). The name is derived from the Greek words helix, helik-, meaning spiral; and pteron meaning wing.

<span class="mw-page-title-main">Quadcopter</span> Helicopter with four rotors

A quadcopter, also called quadrocopter, or quadrotor is a type of helicopter that has four rotors.

<span class="mw-page-title-main">Gyrodyne</span> Type of VTOL aircraft

A gyrodyne is a type of VTOL aircraft with a helicopter rotor-like system that is driven by its engine for takeoff and landing only, and includes one or more conventional propeller or jet engines to provide forward thrust during cruising flight. During forward flight the rotor is unpowered and free-spinning, like an autogyro, and lift is provided by a combination of the rotor and conventional wings. The gyrodyne is one of a number of similar concepts which attempt to combine helicopter-like low-speed performance with conventional fixed-wing high-speeds, including tiltrotors and tiltwings.

<span class="mw-page-title-main">Rotorcraft</span> Heavier-than-air aircraft which generates lift over rotating wings

A rotorcraft or rotary-wing aircraft is a heavier-than-air aircraft with rotary wings or rotor blades, which generate lift by rotating around a vertical mast. Several rotor blades mounted on a single mast are referred to as a rotor. The International Civil Aviation Organization (ICAO) defines a rotorcraft as "supported in flight by the reactions of the air on one or more rotors".

<span class="mw-page-title-main">Helicopter</span> Type of rotorcraft in which lift and thrust are supplied by horizontally-spinning rotors

A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of short take-off and landing (STOL) or short take-off and vertical landing (STOVL) aircraft cannot perform without a runway.

<span class="mw-page-title-main">Sikorsky X2</span> Experimental high-speed compound helicopter

The Sikorsky X2 is an experimental high-speed compound helicopter with coaxial rotors, developed by Sikorsky Aircraft, that made its first flight in 2008 and was officially retired in 2011.

<span class="mw-page-title-main">Volocopter VC2</span> German experimental air vehicle

The Volocopter VC2 is a German single-place experimental electric multirotor personal air vehicle that was built by Volocopter GmbH of Bruchsal, Germany.

ArduPilot is an open source, unmanned vehicle Autopilot Software Suite, capable of controlling autonomous:

Guangzhou EHang Intelligent Technology Co. Ltd is a company based in Guangzhou, China that develops and manufactures autonomous aerial vehicles (AAVs) and passenger AAVs which have entered service in China for aerial cinematography, photography, emergency response, and survey missions.

Krossblade Aerospace Systems is an aviation company founded in 2014 in Phoenix, Arizona, USA. The company is known for developing a 5-seat VTOL concept, SkyCruiser, hybrid vehicle for vertical take-off and landing, and for its drone/UAV prototype, named SkyProwler. Both aircraft employ the switchblade transformation mechanism to transform from a multirotor aircraft for vertical take-off and landing, to a pure winged aircraft, for rapid and efficient cruise.

Urban Air Mobility (UAM) is the use of small, highly automated aircraft to carry passengers or cargo at lower altitudes in urban and suburban areas which have been developed in response to traffic congestion. It usually refers to existing and emerging technologies such as traditional helicopters, vertical-takeoff-and-landing aircraft (VTOL), electrically propelled, vertical-takeoff-and-landing aircraft (eVTOL), and unmanned aerial vehicles (UAVs). These aircraft are characterized by the use of multiple electric-powered rotors or fans for lift and propulsion, along with fly-by-wire systems to control them. Inventors have explored urban air mobility concepts since the early days of powered flight. However, advances in materials, computerized flight controls, batteries and electric motors improved innovation and designs beginning in the late 2010s. Most UAM proponents envision that the aircraft will be owned and operated by professional operators, as with taxis, rather than by private individuals.

<span class="mw-page-title-main">Volocopter 2X</span> German helicopter

The Volocopter 2X is a German two-seat, optionally-piloted, multirotor eVTOL aircraft. The personal air vehicle was designed and produced by Volocopter GmbH of Bruchsal, and first introduced at the AERO Friedrichshafen airshow in 2017. The aircraft is sold complete and ready-to-fly. Volocopter was formerly known as E-volo.

<span class="mw-page-title-main">Workhorse SureFly</span> Vertical take-off and landing aircraft

The SureFly is a two-seat hybrid eVTOL aircraft designed by American truck-manufacturer Workhorse Group, before the program was bought by Moog Inc. for $5 million in December 2019.

References

  1. Early in helicopter development,"multi-rotor" was used to refer to helicopters with two rotor assemblies
  2. "AeroQuad - The Open Source Quadcopter". Archived from the original on 2012-01-03. Retrieved 2012-01-05.
  3. "Multicopter Table". multicopter.org. Retrieved 30 June 2015.
  4. "FrontPage - UAVP-NG - The Open Source Next Generation Multicopter". uavp.ch. Retrieved 30 June 2015.
  5. "FrontPage - UAVP-NG - The Open Source Next Generation Multicopter". uavp.ch. Retrieved 30 June 2015.
  6. "DIY Drones". diydrones.com. Retrieved 30 June 2015.
  7. OpenPilot Archived 2011-05-27 at the Wayback Machine Open source UAV autopilot for multirotors
  8. "How to Pick The Best Multirotor Frame". My First Drone. Archived from the original on 3 April 2014. Retrieved 30 June 2015.
  9. "Octo Quad". ardupilot.org. Retrieved 30 December 2019.
  10. "ALMA Filmed with Hexacopter". ESO Announcement. Retrieved 6 September 2013.
  11. "Multirotor Frame Configurations". Coptercraft. Retrieved 23 December 2015.
  12. Vertical technologies DeltaQuad
  13. QuadRanger VTOL
  14. SkyProwler
  15. Quadplane term
  16. Flight 14 April 1949 p427
  17. "German multicopter makes first manned flight". sUAS news. 1 November 2011. Retrieved 3 Nov 2011.
  18. "Volocopter: 18-propeller electric helicopter takes flight". CNN news. 27 November 2013. Retrieved 2 Dec 2013.
  19. "New Aircraft Arises from Germany". Sport Aviation: 14. January 2012.